Fix shadowing warnings in gcc

example/CMakeLists.txt

@@ -59,6 +59,7 @@ else()
             -Wall
             -Werror
             -Wextra
+            -Wshadow
             -ftemplate-backtrace-limit=0
     )
 

example/main.cpp

@@ -88,7 +88,7 @@ int main() {
 		int some_medadata = 0;
 
 	public:
-		my_rect(const rect_type& rect) : rect(rect) { (void)some_medadata; }
+		my_rect(const rect_type& rect_) : rect(rect_) { (void)some_medadata; }
 
 		/*
 			You need to provide these two member getters.

src/rectpack2D/best_bin_finder.h

@@ -10,7 +10,7 @@ namespace rectpack2D {
 		T first;
 		T second;
 	public:
-		span(T first, T second) : first(first), second(second) {}
+		span(T first_, T second_) : first(first_), second(second_) {}
 
 		T begin() const {
 			return first;
@@ -183,12 +183,12 @@ namespace rectpack2D {
 	) {
 		const auto try_pack = [&](
 			const bin_dimension tried_dimension, 
-			const rect_wh starting_bin
+			const rect_wh candidate_starting_bin
 		) {
 			return best_packing_for_ordering_impl(
 				root,
 				std::forward<O>(ordering),
-				starting_bin,
+				candidate_starting_bin,
 				discard_step,
 				tried_dimension
 			);
@@ -202,16 +202,16 @@ namespace rectpack2D {
 
 		auto best_bin = std::get<rect_wh>(best_result);
 
-		auto trial = [&](const bin_dimension tried_dimension) {
+		auto try_dimension = [&](const bin_dimension tried_dimension) {
 			const auto trial = try_pack(tried_dimension, best_bin);
 
 			if (const auto better = std::get_if<rect_wh>(&trial)) {
 				best_bin = *better;
 			}
 		};
 
-		trial(bin_dimension::WIDTH);
-		trial(bin_dimension::HEIGHT);
+		try_dimension(bin_dimension::WIDTH);
+		try_dimension(bin_dimension::HEIGHT);
 
 		return best_bin;
 	}

src/rectpack2D/rect_structs.h

@@ -6,7 +6,7 @@ namespace rectpack2D {
 
 	struct rect_wh {
 		rect_wh() : w(0), h(0) {}
-		rect_wh(const int w, const int h) : w(w), h(h) {}
+		rect_wh(const int w_, const int h_) : w(w_), h(h_) {}
 
 		int w;
 		int h;
@@ -41,7 +41,7 @@ namespace rectpack2D {
 		int h;
 
 		rect_xywh() : x(0), y(0), w(0), h(0) {}
-		rect_xywh(const int x, const int y, const int w, const int h) : x(x), y(y), w(w), h(h) {}
+		rect_xywh(const int x_, const int y_, const int w_, const int h_) : x(x_), y(y_), w(w_), h(h_) {}
 
 		int	area() const { return w * h; }
 		int perimeter() const { return 2 * w + 2 * h; }
@@ -67,7 +67,7 @@ namespace rectpack2D {
 		bool flipped;
 
 		rect_xywhf() : x(0), y(0), w(0), h(0), flipped(false) {}
-		rect_xywhf(const int x, const int y, const int w, const int h, const bool flipped) : x(x), y(y), w(flipped ? h : w), h(flipped ? w : h), flipped(flipped) {}
+		rect_xywhf(const int x_, const int y_, const int w_, const int h_, const bool flipped_) : x(x_), y(y_), w(flipped_ ? h_ : w_), h(flipped_ ? w_ : h_), flipped(flipped_) {}
 		rect_xywhf(const rect_xywh& b) : rect_xywhf(b.x, b.y, b.w, b.h, false) {}
 
 		int	area() const { return w * h; }